DRAFT UGANDA 
STANDARD  
  DUS DARS  461 
First  Edition  
2022 -mm-dd 
 
 Reference number  
DUS DARS 461: 2022  
 
© UNBS 2022  
   
Maize grains (Corn) — Specification  
 
 
PUBLIC REVIEW DRAFTDUS DARS  461: 2022  
ii                © UNBS  2022  - All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsib le for its correct application  
© UNBS 2022  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
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PUBLIC REVIEW DRAFTDUS DARS  461: 2022  
© UNBS  2022  - All rights reserved                 iii National foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of t he Laws of Uganda, as amended. UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisati on for Standardisation (ISO);   
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standard s; and  
(c) the National Enquiry Poin t on TBT Agreement of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of represent atives of 
consumers, traders, academicians, manufacturers, government and other stakeholders.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the com ments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Draft Uganda Standard , DUS DARS 461:2022 , Maize grains (Corn) — Specification , is identical with a nd 
is being reproduced from an African  Standard , DARS 461:2022 , Maize grains (Corn) — Specification , and is 
proposed for adoption as a Uganda Standard.  
The committee responsible for this document is Technical Committee UNBS/TC 203, Cereals, pulses and 
related products and pr ocesses . 
Wherever the words, “African  Standard " appear, they should  be replaced by "Uganda Standard ". 
  
 
   
PUBLIC REVIEW DRAFTAFRICAN 
STANDARD  DARS  
461  
Third  Edition 20 22 
 
 Reference No. DARS 461:2022(E) 
ICS 67.060  
 
 
© ARSO 202 2 
 
 
 
 
 
 
 
 
 
 
 
Maize  grains  (Corn)  — Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 DARS 461:202 2 (E) 
ii © ARSO 202 2 — All rights reserved   
Table of Contents  
 
4.1 Colour  ................................ ................................ ................................ ................................ .... 3 
5.1  General requirements  ................................ ................................ ................................ ............  4 
5.2 Specific requirements  ................................ ................................ ................................ ............  4 
6.1 Heavy metals  ................................ ................................ ................................ .........................  5 
6.2 Pesticide residues  ................................ ................................ ................................ ..................  5 
10.2 Labelling of non-retail containers  ................................ ................................ ...........................  6 
 
 
 
 
  1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ .....................  1 
3 Terms and Definitions  ................................ ................................ ................................ ....................  1 
4 Classification  ................................ ................................ ................................ ................................ .. 3 
5 Quality requirements  ................................ ................................ ................................ ......................  4 
6 Contaminants  ................................ ................................ ................................ ................................ . 5 
7 Hygiene  ................................ ................................ ................................ ................................ ..........  5 
8 Weights and measurements ................................ ................................ ................................ ...........  5 
9 Packaging  ................................ ................................ ................................ ................................ ....... 5 
10 Labelling  ................................ ................................ ................................ ................................ ..... 5 
11 Methods of sampling  ................................ ................................ ................................ ..................  6 
Bibliography  ................................ ................................ ................................ ................................ ............  7 DARS 461:202 2 (E)  
© ARSO 202 2 — All rights reserved  iii Foreword  
 
The African Organization for Standardization (ARS) is an African intergovernmental organization made 
up of the United Nations Economic Commission for Africa (UNECA) and the Organization of African 
Unity (AU). One of the fundamental mandates of ARSO is to develop and harmoniz e African Standards 
(ARS) for the purpose of enhancing Africa’s internal trading capacity, increase Africa’s product and 
service competitiveness globally and uplift the welfare of African communities. The work of preparing 
African  Standards is normally carried out through ARSO  technical committees. Each Member State  
interested in a subject for which a technical committee has been established has the right to be 
represented on that committee. International organizations, Regional Economic Communities (RECs), 
governmental and non -governmental  organizations , in liaison with ARSO , also take part in the work.  
 
ARSO  Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.  
 
The main task of technical co mmittees is to prepare ARSO  Standards. Draft ARSO  Standards adopted 
by the technical committees are circulated to the member bodies for voting. Publication as an ARSO  
Standard requires approval by at least 75 % of the member bodies casting a vote.  
 
Attenti on is drawn to the possibility that some of the elements of this document may be the subject of 
patent rights. ARSO  shall not be held responsible for identifying any or all such patent rights.  
 
 
This African Standard was prepared by the ARSO Technical Comm ittee on Cereals, pulses and derived 
products  (ARSO/TC 12). 
 
This African Standard is a technical revision of the earlier ARS 461: 2016 (E), Standard for maize (corn) 
which is hereby superseded and cancelled  
 
 
© African Organisation for Standardisation  2022 — All rights reserved* 
 
ARSO Central Secretariat  
International House 3rd Floor  
P. O. Box 57363 — 00200 City Square  
NAIROBI, KENYA  
 
Tel. +254 -20-2224561, +254 -20-311641, +254 -20-311608  
Fax: +254 -20-218792  
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
  
                                                 
* 2022 ARSO — All rights of exploitation reserved worldwide for African Member States’ NSBs. 
 DARS 461:202 2 (E) 
iv © ARSO 202 2 — All rights reserved   
Copyright notice  
 
This ARSO document is copyright -protected by ARSO. While the reproduction of this document 
by participants in the ARSO standards development process is permitted without prior permission 
from ARSO, neither this document nor any extract from it may be reproduced, stored or 
transmitted in any form for any other purpose without prior written permission from ARSO.  
 
Requests fo r permission to reproduce this document for the purpose of selling it should be 
addressed as shown below or to ARSO’s member body in the country of the requester:  
 
 
© African Organisation for Standardisation 2022 — All rights reserved  
 
ARSO Central Secreta riat 
International House 3rd Floor  
P.O. Box 57363 — 00200 City Square  
NAIROBI, KENYA  
 
Tel: +254 -20-2224561, +254 -20-311641, +254 -20-311608  
Fax: +254 -20-218792  
 
E-mail: arso@arso -oran.org  
Web: www.arso -oran.org  
 
Reproduction for sales purposes may be subject to royalty payments or a licensing agreement. 
Violators may be p rosecuted.  
 
 
 
  DARS 461:202 2 (E)  
© ARSO 202 2 — All rights reserved  v Introduction  
 
Maize grain is produced in larger  quantities in Africa more than any other crop.  It is a major food security 
crop in Sub-Saharan Africa, being the  staple food for an estimated 50 per  cent of the population. Maize 
is an important source of carbohydrates, protein, iron, vitamin B, and miner als. 
This standard has been revised to take into account:  
a) the needs of the market for the product;  
b) the need to facilitate fair domestic, regional and international trade and prevent technical 
barriers to trade by establishing a common trading language for  buyers and sellers;  
c) the structure of the CODEX, UNECE, USA, ISO and other internationally significant standards;  
d) the needs of the producers in gaining knowledge of market standards, conformity assessment, 
commercial cultivars and crop production process;  
e) the need to transport the product in a manner that ensures keeping of quality until it reaches 
the consumer;  
f) the need for the plant protection authority to certify, through a simplified form, that the product 
is fit for cross -border and international trade  without carrying plant disease vectors;  
g) the need to promote good agricultural practices that will enhance wider market access, 
involvement of small -scale traders and hence making farming a viable means of wealth 
creation; and  
h) the need to ensure a reliable  production base of consistent and safe crops that meet customer 
requirements . 
This edition has also incorporated several changes in order to align the standard to current requirements 
for quality and safety including  but not limited to  the following aspects:  
 
(i) Limits for mycotoxins  
 
(ii) Microbiological requirements  
 
(iii) Grading of grains  
 DARS 461:202 2 (E) 
© ARSO 202 2 — All rights reserved  1 Maize grains (Corn) — Specification  
 
 
1 Scope  
 
This African Standard specifies the requirements and methods of sampling and test for maize grains  
(corn)  of varieties grown from common maize  grains, Zea mays indentata  L., and/or Zea mays indurata  
L., or their hybrids intended for human consumption .  
 
2 Normative references  
 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the lat est edition of the referenced 
document (including any amendments) applies.  
 
ARS 53, General principles of food hygiene — Code of practice  
 
ARS 56, Prepackaged foods — Labelling  
 
CODEX STAN 193, Codex general standard for contaminants and toxins in food and  feed 
 
ISO 605 , Pulses — Determination of impurities, size, foreign odours, insects, and species and variety 
— Test methods  
 
ISO 711, Cereals and cereal products — Determination of moisture content (Basic reference method)  
 
ISO 712 , Cereals and cereal products — Determination of moisture content — Routine reference 
method  
 
ISO 5223, Test sieves for cereals  
 
ISO 6633, Fruits, vegetables and derived products — Determination of lead content — Flameless 
atomic absorption spectrometric method  
 
ISO 6561 -1, Fruits, vegetables and derived products — Determination of cadmium content — Part 1: 
Method using graphite furnace atomic absorption spectrometry  
 
ISO 6561 -2, Fruits, vegetables and derived products — Determination of cadmium content — Part 2: 
Method using  flame atomic absorption spectrometry  
 
ISO 16050,  Foodstuffs — Determination of aflatoxin B 1, and the total content of aflatoxin B 1, B2, G1 and 
G2 in cereals, nuts and derived products — High performance liquid chromatographic method  
 
ISO 27085, Animal feeding stuffs — Determination of calcium, sodium, phosphorus, magnesium, 
potassium, iron, zinc, copper, manganese, cobalt, molybdenum, arsenic, lead and cadmium by ICP -
AES 
 
AOAC Official Method 2001.04, Determination of Fumonisins B 1 and B 2 in corn and co rn flak es — Liquid 
chromatography with immunoaffinity column cleanup  
 
ISO 24333 , Cereals and cereal products  — Sampling  
 
 
3 Terms and Definitions  
 
For the purpose of this standard the following  terms and  definition s apply . 
  
AFRICAN STANDARD  DARS 461:202 2 (E)  
2 © ARSO 202 2 — All rights reserved  3.1 
maize (corn)  
shelled dried grains of the species Zea mays indentata  L, (dent maize) and/or Zea mays indurata  L, (flint 
maize), or their hybrids  
 
3.2 
flint maize (corn) - 
form of corn whose mature kernel has a smooth, vitreous, appearance and a rather round shape  
 
3.3 
dent maize (corn) - 
form of corn whose mature kernel has the shape of a horse’s tooth with a depression in the crown  
 
3.4 
insect or pest damaged grains  
grain which shows damage or owing attack by rodents, insects, mites or other pests  . 
 
3.5 
stained kernels  
kernels whose natural colour has been altered by external factors. This includes ground, soil or weather 
damaged kernels, which may have dark stains or discolourations with a rough external appearance  
 
3.6 
rotten and  diseased grains  
grains made unsafe for human consumption due to decay, moulding, or bacterial decomposition, or other 
causes that may be noticed without having to cut the grains to examine them  
 
3.7 
discoloured  grain/ kernel  
 kernel which is damaged by heat, frost or water  
 
3.8 
germinated kernel  
kernels showing visible signs of sprouting  
 
3.9 
frost damaged kernel  
kernels which appear bleached or blistered due to exposure of extremely low temperature  and the seed 
coat may be peeling, germs may appear dead or discoloured  
 
3.10 
mouldy kernel  
maize grains with visible mycelial growth on its tip or surface  
 
3.11 
immature/shrivelled grains  
maize grains which are underdeveloped, thin and papery in appearance  
 
3.12 
broken kernels  
pieces of maize which shall pass through a 4.50 mm metal sieve  
 
3.13 
other edible grains  
edible grain, whole or broken, other than maize, that is, cereals, pulses and other edible legumes   
 
3.14 
foreign matter /extraneous matter  
all organic and inorganic material s other than maize   DARS 461:202 2 (E) 
© ARSO 202 2 — All rights reserved  3 3.14.1 
inorganic foreign matter  
inorganic matter components , such as stone, sand and dust  
 
3.14.2 
organic foreign matter  
any animal or plant matter (e.g. dead insects, seed coats, straws, weeds) other than grain of maize and 
damaged maize grain  
 
3.15 
filth 
impurities of animal origin  including dead insects  
 
3.16 
defective grains  
pest damaged, discoloured, stained, rotten and diseased, immature and shrivelled grains and broken 
grain  
 
3.17 
food grade packaging material  
packaging material, made of substances which are safe and suitable for their intended use and which 
will not impart any toxic substance or undesirable odour or flavour to the product  
 
3.18 
heat damaged maize grains  
maize grains which are discoloured and damaged by excess ive high temperature.  
 
3.19 
poisonous, toxic and/or harmful seeds  
seed which if present  in quantities above permissible limit may have damaging or dangerous effect on 
health, organoleptic properties or technological performance such as Jimson weed — Datura ( D. 
fastuosa  Linn and D. stramonium  Linn.) corn co ckle ( Agrostemma githago  L., Machai Lallium 
remulenum  Linn.) Akra (Vicia  species), Argemone mexicana , Khesari and other seeds that are 
commonly recognized as harmful to health  
 
 
4 Classification  
 
Maize  kernels shall meet the following general requirements as determined using the relevant standards 
listed in Clause 2, kernels shall be  
 
4.1 Colour   
 
Maize may be presented as yellow, white, or red, or a mixture of these colours.  
 
a) Yellow maize shall contain not more than 5.0 % by weight of maize of other colours. Maize grains 
which are yellow and/or light red in colour are considered to be yellow maize. Yellow maize also 
means maize grains which are yellow and dark red in colour, provided the dark red  colour covers 
less than 50 % of the surface of the grain.  
 
b) White maize shall contain not more than 2.0 % by weight of maize of other colours. Maize grains 
which are white and/or light pink in colour are considered to be white maize. White maize also 
mean s maize grains which are white and pink in colour, provided the pink colour covers less than 
50 % of the surface of the grain.  
 
c) Red maize shall contain not more than 5.0 % by weight of maize of other colours. Maize grains 
which are pink and white, grey or dark red and yellow in colour are considered to be red maize, 
provided the pink or dark red or yellow colour covers 50 % or more of the surface of the grain.  
 DARS 461:202 2 (E)  
4 © ARSO 202 2 — All rights reserved  d) Mixed maize includes maize not falling into the classes of white, yellow or red maize as defined 
in (a) to (d). 
 
4.2  Shape  
 
Maize also may be presented as flint or dent or their hybrids or mixtures thereof  as follows . 
 
a) Flint maize have kernels with a hard outer layer enclosing the soft endosperm which consist of 
95% or more by weight of flint maize and not more than 5% maize of other shapes by we ight. 
 
b) Dent maize is maize with a concavity on the outermost face of the grain, consists of 95% or 
more by weight of grains of dent maize and not more than 5% maize of other shapes by weight.  
 
c) Flint and dent maize includes maize of any colour which consists of more than 5 % but less than 
95.0 % of flint maize.  
 
 
5 Quality requirements  
 
5.1  General requirements  
 
Maize shall be  practically  free from foreign odours, moulds, live pests, rat droppings, toxic or noxious 
weed seeds and other injurious contaminants as determined from samples representative of the lot . Maize 
shall be of a reasonably uniform colour according to type, be whole and c lean.  
 
5.2 Specific requirements  
 
Maize grain shall comply with maximum limits given in Table 1 when tested in accordance with the test 
methods specified therein .  
 
Table1 ― Specific requirements  
 
S/N Characteristics ,  Limits , max  Method of test  
Grade 1  Grade 2  Grade 3  
(1) Foreign matter, % m/m  0.5 1.0 1.5 
ISO 605  
 (2) Inorganic matter, % m/m  0.25 0.5 0.75 
(3) Broken kernels, % m/m  2.0 4.0 6.0 
(4) Pest damaged grains, % m/m  1.0 3.0 5.0 
(5) Rotten & diseased grains, % m/m  1 2 3 
(6) Discoloured grains, % m/m  1.5 2 2.5 
(7) Moisture, % m/m  13.5  13.5  13.5 ISO 711/712  
(8) Immature/shrivelled grains, % m/m  1.0 2.0 3.0 
ISO 605  
(9) Filth, % m/m  0.1 0.1 0.1 
(10) Total Aflatoxins, ppb, max  10  
ISO 16050  
(11) Aflatoxin B1, ppb, max  5  
(12) Fumonisin, ppm, max  2  AOAC Official Method 
2001.04  
(13) Total a defectives grains, % m/m  5.1 10.2  15.3 ISO 605  
a The parameter, total defective grains is not the sum total of the individual defects. It is limited to 70% of the sum total o f individual 
defects  
NOTE  Maize grains destined for processing baby foods shall have total aflatoxin level of not more than 4 ppb.  DARS 461:202 2 (E) 
© ARSO 202 2 — All rights reserved  5 6 Contamina nts 
 
6.1 Heavy metals  
 
Maize grains shall comply with those maximum limits for metal contaminants specified in CODEX STAN 
193 and in particular those listed in Table 2.  
 
Table 2 — Metal contaminants  
 
S/N Parameter  Limit (ppm max)  Test method  
(1) Lead (Pb)  1.0 ISO 6633 ( AAS)  
(2) Cadmium (Cd)  0.1 ISO 6561 -1 or 6561 -2 
 
 
6.2 Pesticide residues  
 
Maize grains shall comply with those maximum pesticide residue limits established by the Codex 
Alimentarius Commission for this commodity .  
 
 
7 Hygiene  
 
Maize grains shall be produced and handled under hygienic conditions in 
accordance with ARS 53 . 
 
 
8 Weights and measurements  
 
Maize grains shall be packaged in accordance with the weights and measures regulations of the 
destination country.  
 
NOTE Maximum package weight of 50 kg where human loading and offloading is involved’  
 
 
9 Packaging  
 
9.1 Maize grains shall be packed in suitable p ackages which shall be clean, sound, free from insect, 
fungal infestation and the packing material shall be of food grade quality  and shall be securely closed 
and sealed.   
 
9.2 Maize grains shall be packed in containers which will safeguard the hygienic, nutritional, and 
organoleptic qualities of the products.  
 
9.3 Each package shall contain maize grains of the same type and of the same grade designation.  
 
9.4 If maize grains are presented in bags, the bags shall also be free of pests and contaminants.  
 
 
10 Labelling  
 
10.1 The following specific labelling requirements shall apply and shall be legibly and indelibly 
marked in accordance with the requirements of ARS 56:  
 
i) product name as “White Maize Grains, Yellow Maize Grains, Red Maize Grains or Mixed Ma ize 
Grains”;  DARS 461:202 2 (E)  
6 © ARSO 202 2 — All rights reserved   
ii) grade;  
 
iii) name, address and physical location of the producer/ packer/importer;  
 
iv) lot/batch/code number;  
 
v) net weight, in kg;  
 
vi) the declaration “Food for Human Consumption’’  
 
vii) storage instruction as “Store in a cool dry place away from any contaminants’’;  
 
viii) crop year;  
 
ix) packing date;  and expiry date  
 
x) instructions on disposal of used package;  
 
xi) country of origin;  
 
xii) a declaration on whether the maize was genetically modified where applicable.  
 
10.2 Labelling of non -retail containers  
 
Information for non -retail containers shall either be given on the container or in accompanying 
documents, except that the name of the product, lot identification and the name and address of the 
manufacturer or packer sh all appear on the container. However, lot identification and the name and 
address of the manufacturer or packer may be replaced by an identification mark, provided that such a 
mark is clearly identifiable with the accompanying documents.  
 
 
11 Methods of sampling  
 
Sampling shall be done in accordance with the ISO 24333 . 
 
  DARS 461:202 2 (E) 
© ARSO 202 2 — All rights reserved  7 Bibliography  
 
 
EAS 2:201 2, Maize grains — Specification  
 
Cereals Grading and Marking Rules, 2001 , Ministry of Agriculture, Government of India, Schedule V, 
Grade Designation and Definition of Quality of Maize  
 
CODEX STAN 153:1985 (Rev.1:1995), Standard for Maize (Corn)  
 
Corn,  Official Grain Grading Guide, August 1, 20 12, Canadian Grain Commission  
 
United States Standards for Corn , Effective September 1996  
 
Malawi Standard, MBS 32:1998, Maize grain — Specification  
 
Ethiopian Standard, ES 679:2001, Maize (corn) — Specification  
 
CODEX STAN 193:1995 (Rev.5:2009), General standard for contaminants and toxins in foods  
 
CODEX STAN 228:2001 (Rev.1:2004), General methods of analysis for contaminants  
 
 
 
 
 DARS 461:202 2 
© ARSO 202 2 — All rights reserved